Air-compressor.



(LIA. V. CARLSSONL AIR COMPRESSOR. APPLICATION men MAY 24. I916.

Patented May 7,1918.

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Ill/MENTOR w; arm;

ii/40% AK A non/v5 rs C. A. V. CARLSSON.

AIR COMPRESSOR. APPLICATIONFILED MAY24|1916- Patented May 7,1918.

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WTTOBIVEYS C. A. V. CARLSSON.

AIR COMPRESSOR. APPLICATION FILED. MAY 24. l9l6- Patented May 7,1918.

4 SHEETS-SHEET 3- I IIII llllll ATTORNEYS C. A. V. CA-HLSSON.

AIR COMPRESSOR. APPLICATION man MAY 24. L916.

Patented May 7,1918.

4 SHEETS-SHEET 4.

" 794/ race/IRI- l/WE/IITOR W MW WITNESSES:

ATTORNEYS NlTE CARL A. V. CARLSSOILOF WASHINGTON, DISTRICT OF COLUMBIA.

AIR-COMPRESSOR.

1,265.,tldd.

Specification of Letters Patent.

Application filed May 24, 1916. Serial No. 99,611.

To all whom it may concern:

Be it known that I, CARL A. V. CAnLssoN, a citizen of the United States,and a resident of the city of Vvashington, in the District of Columbia,have invented a certain new and useful Improvement in Air-Compressors,of which the following is a specification.

My invention relates to improvements in air compressors, and it consistsin the combinations, constructions, and arrangements herein describedand claimed.

An object of my invention is to provide an air compressor which willdeliver air to a storage tank in such quantity as to keep up thepressure in the storage tank to a predetermined point even if the air isused in greater quantity at certain times than at other times.

A further object of my invention is to provide a device of the typedescribed in which valves are usedwhich are automatically operated bythe air itself, means being provided to hold open certain of the valves,as for instance, the suction valves during the whole or a part of thecompression stroke of the piston, so that all or a part of the air takeninto the cylinders will be pushed back into the suction chest instead ofthe delivery pipe leading to the storage tank or receiver.

A further object of my invention is to provide a device of the typedescribed in which comparatively simple apparatus is used to accomplishthe control of the valves.

Other objects and advantages will appear in the following specification,and the novel features of the invention will be particularly pointed outin the appended claims.

My invention is illustrated in the accompanying drawings forming part ofthis application, in which:

Figur 1 is a plan view of a portion of the device, certain parts beingshown in section. T Fig. 2 is a section along the line 2-2 of Fig. 3 isan enlarged view of a portion of the device shown in Fig. 2.

Fig. 4 is an enlarged section on the line 44 of Fig. 3. 1FFig. 5 is asection along the line 5-5 of Fig. 6 is a section along the line 6-6 ofis detailed view, partly in section.

showing the actuating means for the valve control members.

Fig. 8 is a sectional detail view showing the operation of the valves.

Referring now particularly to Fig. 1, I have shown therein a cylinder 1which is provided with a piston 2 and with intake valves 3 and exhaustvalves 4, see Fig. 8. The intake valves communicate with an intakemanifold, while the exhaust valves are connected to the tank or receiver6 from which a pipe 7 may lead to the place where the air is to be used.

The description thus far is that of the ordinary air compressor. It maybe stated here that the invention is designed to apply to various typesof air compressors, but the one illustrated in the accompanying drawingsis typical of many forms that might be devised which would work on thesame principle.

The valves which are used in connection with the preferred form of aircompressor are those of the so-called feather valves which are common inthe art. In Fig. 1 I have shown an intake valve and an ex aust valve.

The means for controlling the valves is operated from the cross head, inthis particular instance. In Fig. 7 I have shown a portion of the crosshead 8 which is arranged to be moved back and forth in the ordinarymanner and which in its movement tends to give to a grooved rod 9 anoscillatory movement about its axis. The rod 9 is provided with an arm10 which is connected by means of a link 11 with the arm 12 secured atthe end of a shaft 13 which is journaled in bearings 14 at one end, theopposite end of the shaft extending through a sleeve 15, see Fig. 4, andbeing feathered to the sleeve so as to permit a longitudinal movement ofthe sleeve with respect to the shaft, while communicating theoscillatory movement of the shaft to the sleeve.

The sleeve 15, as will be seen from Fig; 4:, is provided with astationary collar 16 near its center, and with a removable collar 17,between which collars a yoke 18 is disposed, which yoke is at the end ofa lever 18 pivotally mounted at and arranged to be operated so as tomove the sleeve longitudinally with respect to the shaft 13.

Thesleeve isprovided with a series ofhelical Patented May 7, llfi ild. I

grooves 15 at one end and a similar series of grooves 15 at the otherend, the grooves 15*, however, running in one direction around thesleeve, and the grooves 15 running in the other direction.

The grooved sleeve 15 is arranged to enter the interior of the hubs 19and 20 of the cam members 19 and 20 respectively. These hubs are mountedfor revolution in bearings 19 and 20 respectively. It will be observedthat the grooved sleeve is in enga ement with the inner end of the hubs19 and 20 respectively, so that when the sleeve is moved longitudinallywith respect to the shaft 13 it will cause the simultaneous revolutionof the hubs 19 and 20 of the cam members 19 and 20 respectively, aroundtheir axes, but in opposite directions.

In Fig. 3 I have shown in detail one of these cam members, to wit, thecam member 20. This, as will be seen, is a cylinder having on one side acam surface 20. A cam roller 21 is mounted on a bell crank lever 22which is pivoted at 23 and is connected by means of a link '24 with thebell crank lever 25 pivoted at 26. The end of this bell crank lever 25is arranged to engage a slidable pin 27 Whose head bears normally on theend of a lever 28 which is pivotally mounted at 29. This lever 28 bearsa cross bar 30 bearing pins 31 arranged to extend through openings 32,see Fig. 1, these openings being controlled by feather valves 33 likethat shown in Fig. 2. A spring 34 is secured to the lever 28 and tendsto hold the latter "and the bar 30 bearing the pin 31 away from thevalve 33. It will be obvious, however, that if the bell crank lever 25is moved so as to force the rod 27 inwardly, the pins 31 will be forcedinwardly, thereby pressing the valves 33 from their seats.

The shifting of the sleeve 15 by means of the lever 18 is accomplishedby means of air pressure through the medium of a mechanism, the specificconstruction of which forms no part of the present invention, the samebein'g old in the art. I will therefore refer only to the essentialparts.

Considering then Fig. 6, it will be seen that I have provided a pipe 35leading from the air receiver, and communicating with a cylinder 36having'a plunger 37. A weight 37 has an *arm 37, see Figs. 2 and *6. Theupper end of this arm is bent over the end of theplun'ger 3'7 and isprovided with a suspending member, 'such as the screw 37, by means Ofwhich the force of the weight is directly applied to the plunger. Aspring 38 surrounds the upper end 'of the plunger and also tends to aidin exerting a '-'downward force *o'n t'he plunger. The purpose of "thespring, however, is mainly that of adjustingtlre farce exerted theplunger,

which tends to resist the air pressure in the manner hereafterexplained. A yoke 39 is engaged by a collar on the plunger and opcratesa bell crank lever 40 whose end is connected by means of a link 41, seeFigs. 1 and 4, with a lever 42 pivotally mounted at 43 on the largelever 18. The lever 42 is connected by a link 44 at its end with a lever45 which is pivotally mounted at 46. It will be seen from Fig. 2 thatthis has its arms at the end of the central pivot portion 46, so thatthe arms do not lie in the same plane. One end of the lever is providedwith a head 45 which enters a recess in a slidable valve member 47disposed in a valve casing 48.

From the foregoing description of the various parts of the device, theoperation thereof may be readily understood.

Let use assume that we wish the pressure in the receiver 6 to be kept at100 pounds. \Vith the apparatus as shown in the drawings, the suctionvalves 3 will operate in the ordinary manner; that is to say, they willopen at the first forward stroke of the piston, remain open during theentire stroke, and close during the reverse stroke, so that air isforced from the cylinder through the delivery pipe 4 see Fig. 8, pastthe outlet valve 4, until the pressure reaches the desired point. Duringthis time the rod 13 is oscillating in the manner already described, butthe roller 21 (see Fig. 3) is riding on the lower part of the cam 20 onthe arc of a circle, and therefore there is no movement of the bellcrank lever 22 or of the rod 24 which transmits the movement of the bellcrank lever to the pin for holding open the valve.

When 110w the pressure reaches the desired point, the force of theweight 37 a and spring 38, will be overcome, so that the air pressurewill force the plunger 37 upwardly against the action of the weight,thereby moving the bell crank lever 40 and causing the link 41 to moveto the left, in Figs. 6, 4 and 1. This will swing the lever 42, which,as stated, is mounted on the lever 18"-, toward the left, and throughthe medium of the link 44 and the lever'45, will move the valve member47 toward the right in Fig. 4. Let us consider the condition just beforethe valve is moved to the right in Fig. 4. At 50 and 51 at opposite endsof the valve casing, I have shown pipes which communicate with thereceiver for admitting air into the interior of the auxiliary cylinder52. The latter is provided with a plunger 53 to which the large levers18 are pivoted at 20". With. the position of the valve shown in Fig.4,air is admitted to both ends of this plunger, and the pressure beingequal there is no tendency for the plunger to shift. When, however, thevalve 47 is moved to the right," then the left end of the cylinder isopened to the exhaust 54 and is closed to the pressure coming throughthe pipe 51, while the pressure coming through the pipe 50 still hasaccess to the end of the plunger 53 and it will thereby force the lattertoward the left in Fig. 4. The end of the lever 18 is fulcrumed at 55,see Fig. 4, so that as the plunger 53 moves toward the left, the leverwill swing so as to shift the sleeve 15 toward the left, thereby causingthe rotation of the cam members 19 and 20 in opposite directions, so asto bring the am surfaces which are similar to that shown at 20 in Fig. 3underneath the roller 21, thereby moving the roller, the bell cranklever, the link 24, bell crank lever 25, rod 27 and pins 31 so as toengage the feather valves 33 and hold them open as long as the roller ison the high part, 2'. 6., the part corresponding to 20 of the cam. Thevalve being held open, of course the a1r is merely drawn into thecylinder of the compressor and then is forced out through the same valvewhere this automatic controlling device is arranged in connection withthe suction valve.

Obviously it is a mere matter of adjustment to cause the suction valvesto be held open beginning at any point with the stroke of the piston,and such adjustment will be made to suit different conditions.

When the lever 18 is moved by the movement of the plunger 53 toward theleft, the lever 42 which is pivoted to the lever 18 at 43, will be swungtoward the right, due to the fact of its connection to the link 41. Thiswill move the valve engaging end of the lever 45 to the left and willcarry with it the valve member 47 so as to bring it into the positionshown in Fig. 4, in which pressure is admitted to both ends of theplunger 53, thereby holding the plunger in position.

When now the pressure in the receiver falls below the predeterminedamount, then the weight 37* will cause the plunger 37 to move in theopposite direction, thereby moving the bell crank lever 40, link 41, andlever 42 to the right in Fig. 1, thus moving the lever 45 to the leftand permitting the air at the right end of the cylinder to dischargethrough the discharge outlet 47. This will cause the movement of theplunger 53 to the right carryin with it the lever 18 and causingmovement of the sleeve 15 and rotation of the cams in the oppositedirection. As the stroke is being completed, the lever 42 will beshifted to the left, thus bringing the valve member 47 into the neutralposition and admitting air into both ends of the cylinder 52, therebyholding the plunger in position.

I am aware that it is old to govern the amount of air delivered from anair compressor by controlling the opening, of the valves broadly, butthis device relates more particularly to the automatic control of valveswhich normally are operated by the air pressure, or so-called automaticvalves as distinguished from positively operated valves.

There is one feature to which I desire to call articular attention. Theposition of the plunger 37 depends, of course, upon the pressure of theair or motive fluid, which enters through the pipe 35. The greater themovement of the plunger, the more the spring 38 is compressed, thustending to resist the movement. The levers 19 which operate the plunger53 move in accordance with the movement of the plunger 37, so that-theaction of the plunger 53 is not a sudden one, but takes place graduallyand is in strict relation to the plunger 37. It will be seen, therefore,that the opening of the valves is dependent upon the pressure in thereceiver and is automatically regulated by this pressure.

I claim 2- 1. The combination with an air compressor having a series ofair controlled valves, of a receiver connected with said compressor, andmeans controlled by the pressure in the receiver for holding opencertain of said valves during a period when the valves are otherwisenormally closed, said means including a stop finger, a cam roller, anoscillated cam, connections between said cam roller and said stop fingerfor operating the latter, means operated by the air from said receiverfor shifting the position of the cam, said last-named means comprising asleeve having spirally arranged engaging members for engaging the cam,and means for moving said sleeve longitudinally of its axis to cause therotation of the cam.

2. The combination with an air compressor having a series of aircontrolled valves, of a receiver connected with said compressor, andmeans controlled by the pressure in the receiver for holding opencertain of said valves during a period when the valves are otherwisenormally closed, said means including a stop finger, a cam roller, anoscillated cam, connections between said cam roller and said stop fingerfor operating the latter, means operated by the air from said receiverfor shifting the position of the cam, said last-named means comprising asleeve having spirally arranged engaging members for engaging the cam,and a lever for mov ing the sleeve longitudinally of its axis therebycausing the rotation of the cam.

3. The combination with an air compressor having a series of aircontrolled valves, of a receiver connected with said compressor, andmeans controlled by the pressure in the receiver for holding opencertain of said valves during a period when the valves are otherwisenormally closed, said means including a stop finger, a cam roller, anoscillated cam, connections between said cam roller and said stop fingerfor operating the till latter, means operated by the air from saidreceiver for shifting the position of the cam, said last-named meanscomprising a sleeve having spirally arranged engaging members forengaging the cam, a lever for moving the sleeve longitudinally of itsaxis thereby causing the rotation of the cam, and a plunger operated bythe pressure of the air from the receiver for moving said lever.

i, The combination with a compressor having a cylinder provided withautomatic air valves at each'end thereof, a receiver connected with saidcompressor, means for holding certain of said valves at each end of thecylinder open during a'period when they are otherwise normally closed,said means comprising stop fingers, a pair of cams for operating saidstop fingers, and means operated by the pressure from said receiver forrotating said cams about their axes in opp.o site directions and to thesame extent.

5. The combination with a compressor having a cylinder provided withautomatic air valves at each end thereof, a receiver connected with saidcompressor, means for holding certain of said valves at each end of thecylinder open during a period when they are otherwise normally closed,said means com-prising stop fingers,-a pair of cams for operating saidstop fingers, and means operated by the pressure from said receiver forrotating said cams about their axes in opposite directions and :to thesame extent, said last-:namedineans comprising a sleeve having helioally{arranged members on the out- Ooples of this patent may be obtained forside surface thereof, one end of said sleeve having said helical membersextending in one direction around the sleeve and the'opposite end havingthe helical members extending in the reverse direction, and engagingportions of the cam, and means for shifting the sleeve longitudinally ofits axis in either direction, thereby causing the rotation of the camsin opposite directions.

6. The combination with a compressor having a cylinder provided withautomatic air valvesat each end thereof, a receiver connected with saidcompressor, means for holding certain of said valves at each end of thecylinder open during a period when they are otherwise closed, said meanscomprising stop fingers, a pair of cams for operating said stop fingers,and means operated by the pressure from said receiver for rotating saidcains about their axes in opposite directions and to the same extent,said last-named means comprising a sleeve having helically arrangedmembers on the outside surface thereof, one end of said sleeve havingsaid helical members extending in one direction around the sleeve andthe opposite end having the helical members extending in the reversedirection, and engaging portions of the cam, means for shifting thesleeve longitudinally of its axis in either direction, thereby causingthe rotation of the cams in opposite directions, and means for holdingthe sleeve stationary until the pressure in the receiver reaches apredetermined point.

CARL A. V. CARLSSON.

five cents each, by addressing the Commissioner of I'atemp, Washington,D.=G."

